Context: We hypothesized that insulin resistance, even with normal body weight (body mass index or waist circumference), can aggravate periodontitis severity.
Objective: We investigated the associations between diabetes, insulin resistance, and severe periodontitis.
Design: Among 29 235 total participants, 5690 subjects aged ≥ 30 y who had periodontal disease with community periodontal index (CPI) of 3 or 4 were selected for this study.
Participants: Data were derived from the 2008-2010 Korea National Health and Nutrition Examination Survey.
Results: Patients diagnosed with type 2 diabetes were more likely to have severe periodontitis (CPI 4) compared with patients with normal glucose tolerance or impaired fasting glucose (P < .001). Subjects with severe periodontitis had significantly higher prevalence of abdominal obesity, serum triglycerides, and insulin resistance (P values of .012, <.001, and .003, respectively). The odds ratios (ORs) for prevalence of severe periodontitis were significantly increased from normal glucose tolerance and impaired fasting glucose (OR = 1.32; 95% confidence interval, 1.06-1.64) to type 2 diabetes (OR = 1.5; 95% CI, 1.11-2.02), after adjusting for potential confounders (P for trend = .003). The prevalence of severe periodontitis increased significantly with increasing insulin resistance (P for trend = .04) in nondiabetic individuals. Furthermore, insulin-resistant individuals with normal waist circumference showed significantly higher odds of severe periodontitis (OR = 1.47; 95% CI, 1.16-1.87) than did insulin-sensitive individuals with normal waist circumference.
Conclusions: Non-abdominally obese subjects with insulin resistance were more likely to have severe periodontitis. Insulin resistance can be considered an independent risk factor of periodontal disease in normal weight population defined by abdominal obesity.